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H. A. GARDNER.

FABRIC FOR AIRSHIPS ND PROCESS 0F MAKING SAME. APPLrcATloN msn JAN.6,1920.

'1,381, 41 2, mma June 14,1921.

Gas film (rubber) UNITED STATES Partnr or.

.HQE

HENRY A. GARDNER, OF IASIINGTON, ISTRIGT OF COLUMBEA.

FABRC FOR ARSEEPS ANB PROCESS OEE' MAKING SAME.

Specification of Letters Patent.

Patented June 14, 19211.

Annlicaton filed January 6, 1920. Serial No. 349 S36.

' This invention relates to airship fabrics and 'process of making thesame and an object of the invention is to provide a fabric which willnot deteriorate due to the action of light' and heat. l

Another object of the invention is to provide an elastic, vimperviousfabric of low diffusion to prevent the escape of gas.

Another object of the invention is to provide a novel process ofmanufacture of the fabric.V

A further object of the invention is to provide a novel processofmanufacture of the fabric wherein the fabric may e treated at intervals,thus avoiding the expense of new fabric. Y

A irships of the non-rigid type are usually constructedL of fabric madeof cotton that has been. proofed with rubber. For instance, a fabricthat has been found highly satis`h factory forthis purpose and that isbeingr used to a great extent at the present time Yhas the followingconstruction:

@utside proofing;` and aluminum powder Outside ply (straight cloth) (iasiilm (rubber) Middle ply (bias cloth) Inside ply (straight cloth) Total15.4

Vffltreiigth: Warp--SO lbs. per inch width.

iFilling-70 lbs. per inch width.

Permeability: 15 liters of hydrogen per square meter in V2li hours at250 C.

The drawingis a sectionalviewY of a portion of the'fabrio illustratingthe arrangement of the substances or material applied thereto.` Themiddle ply, designated at 10, is coated on both sides with rubber,forming gas films 11. The outer ply 12 of straight clothV adheres to thegas film 11 and is coatedl with rubber proofing containing aluminumpowder to form a film for layer 13. The in-7 ner ply 1a' of straightcloth also adheres to the gas film 11 and is coated with rubberproofing, forming` a film rElie film 13 is coated with dope solutions toform films or layers 16 and 17, as hereinafter` described.

y.Due to the action of light and heat, the rubber proofing used inrubberized fabrics becomes oxidized and breaks down after a Vperiod oftime. A brittle fabric of high diffusion then results. and rapid leakageof hydrogen takes place. buch a result makes s large quantities itnecessary to feed the s' of gas, daily, in order to leep up the purityand lifting power.. if tie fabric becomes acted upon to great extent, itbecomes rotted and is unsafe for use.

@n fabric that is showing` deterioration, it has previously beenproposed to use a dope consisting of nitro-cellulose Y dissolved in amylacetate and similar solvents. .TWhen live coats ofsuch dope are applied,the diffusion is greatly lowerd. but exposure of the doped fa' :ic mayresult in the breaking up of the nitro-cellulose and the formation ofsmall amounts of free nitric acid which will cause rotting' of thecotton cloth.

l have found that after long use, a fabric that is startiA j to exhibitsi ,ons of decay may be preservec from further def y by the applicationof special oil dope .free from inleredients l acid compounds.

containingr minerai i have, moreover, found that linseed oil and similaroils impractical for use as dopes due to the oxygen absorotion of suchoils and their consequent effect uponthe rubberized fabric. The oil iuse in the dope lhave referred (to,l is tung' oil, a product whirh drieslarg-ely through polymerization rathersthan oxidation. my process, Iheat tung oil in a lrettle until it becomes very heavy bodied, but i donot bring` it to such a temperature that polymerization to a solid masswill taire place, Duringthe process of heating", l may add a smallpercentage of Vresin for example, ester gum and certain metallic driers,such as cobalt, lead or manganese linoleates or resinates and then thindown with suitable volatile or other thinners. The resulting dope isthen ready for use. Y l

Vniny process, I first apply one coat of tung oil dope that is rich inresins. This coating or film, designated in the drawing at 16 ispreferably of the following compositionz-ester gum 150 parts, tung oil,15() carts ininerai spirits 220 parts. 'lhis dope dries very rapidly anddue to this property prevents the softening of the rubber prooiing enthe fabric. l then apply one coat of a similar type of tung oil dopethat is 10W in resins and rich in oil. rlhis dries in from 2 to l hours.

ller instance7 with rubberized airship fabric having` a diffusion of 15liters in 24: hours, the application of two coats of the above types ofdope produces a fabric having a diifusioii of only 2 liters. Exposuretests of such fabric over a period of several months7 exposed directlyto the sun and heat, have shown but slight loivering of this resuit.

will be understood that the process of manufacture may be varied inunessential particulars, and that equivalent ingredients Vto preciseproportions of materials 01 to other unessential limitations butcontemplate such variations as are within the principles of the'invention as set forth in the appended claims. a

ifilhat claim is:

1. ifi fabric of the class described coinprising a basic material ofcloth proofed with rubber and a ilm elastic impervious oil on saidrubber.

il fabric as set forth claim 17 and a second 'ihn of elasticiiiipeivious oil on said first-named film.

ifi fabric as set forth in claim l, said lilin of elastic impervious eilhaving a high percentage of resin.

Ki. .7i as set forth in claim 2, said secon-:l iilin eff oil having alow percentage [El l'lslll.

i nl. (i.

ic as .et forth in claim il, said iii-st named film of oil ha'. ing highpercentage resin.

(l. A fabric of the class described. comprisiniv a basicI inaterial ofcloth proofed with rubber and an elastic impervious film of funi' oil ensaid rubber.

f .fi fabric as set forth iu claim 6 and a ,a nd elastic impervious filmof tung oil ou said first named liliu of oil.

. 8. ii fabric as set forth in claiin 7, said first named film of tung`oil having a high percentage of resin, and said second named lilin oftung oil having` a low percentage of resin.

9. The fabric of the class described coinprising a basic material ofcloth proofed with rubber and a film of oil of the class oil driers 15parts, turpentine 50 parts,l

isisiis -"-fliich dries by polymerization on said rubber.

l0. The fabric set forth Vin claim 9 and a second iiiin of oil of theclass Which dries by polymerization on said hist named iilin.

il. vlhe fabric as set forth in claim 9, said lilin of oil having a highpercentage of resin.

'llio fabric as set forth in claim 10, said second film of eil having alow percentage resin.

'lfhe fabric as set forth in claim 11, said first-named lilin of oilhavingl a high percentage of resin.

i process of making airship fabric which consists iii coating' a basicmaterial proofed with rubber with ilin of oil of the class which driesby polymerization.

The Jroccss as set forth in claim 1a im lufY 'the application of asecond film of oil on said irst named film.

rThe -process as set forth in claim 14, nained li n of oil having a highe of resin. is process set forth in claim 15, said sec-A id film of oilhaving a small percentage of resin.

'ihe process as set forth in claiin 15, said hrst lied iilin of oilhaving a high resin. and said second named Q haring a low percentage ofresin. Aprocess of main-ng airship fabric which consists in coating abasic' material proofed writh rubber, with an elastic impervious .flinof tung oil.

The process as seJ {oi-th in claim 9 inf the application of a secondelastic impervious lin of tung oil on said first named lin.

The. process as set forth in claim 9 said film of tung oil having a highpercen+- of resin.

. ie process as set forth in claim 29, second i'ilm of oil having a lowpercentresia.

a The process as set forth in claiin 20. said first film of tung oilhaving; a high percentena of resin. s'aid second named film of tune` oilhaving a low percentage of resin.

F24- .lho process of :making airship 1fabrics having a base of clothproofed with rubber. v rensists .io heating to a heavy consisteiicv anoil of the class which dries by polymerization. adding variablequantities of resin. thinning' the resultant mixture With a suitablevolatile thinner to produce a dope and applying said dope to said rubberproofed base.

Signed at VVashinQgton, District of Columbia., this 3d day of December.1919.

HENRY A. GARDNER.

chui-

